WEDNESDAY, Jan. 11 (HealthDay News) -- The first major gene mutation associated with an increased risk for hereditary prostate cancer has been identified by scientists.

Men who inherit the mutation in the HOXB13 gene have a 10 to 20 times increased risk of developing prostate cancer, according to the study in the Jan. 12 issue of the New England Journal of Medicine.

The HOXB13 gene plays an important role in the development of the prostate during the fetal stage and in prostate function later in life.

The discovery of this gene mutation may help improve understanding about the development of prostate cancer and which men may require early screening for the disease, according to the team led by investigators at the Johns Hopkins University School of Medicine and the University of Michigan Health System.

The researchers analyzed DNA from the youngest prostate cancer patients in 94 families that had multiple cases of the disease among close relatives, such as fathers, sons and brothers. Members of four different families were found to have the same mutation in the HOXB13 gene. All 18 patients in those four families had the mutation.

The investigators then looked at 5,100 men who had been treated for prostate cancer and found that 1.4 percent (72) of them had the same HOXB13 gene mutation. The men with the mutation were much more likely to have at least one first-degree male relative (father or brother) who also had been diagnosed with prostate cancer.

When they looked at a control group of 1,400 men without prostate cancer, the study authors found that only one of the men had the mutation.

The researchers also looked at data from men enrolled in studies of early-onset or familial prostate cancer.

"We found that the mutation was significantly more common in men with a family history and early diagnosis compared with men diagnosed later, after age 55, without a family history. The difference was 3.1 percent versus 0.62 percent," Dr. Kathleen Cooney, a professor of internal medicine and urology at the University of Michigan Medical School, and one of the study's two senior authors, said in a Hopkins news release.

"It's what we've been looking for over the past 20 years," added fellow senior author William Isaacs, a professor of urology and oncology at the Johns Hopkins University School of Medicine. "It's long been clear that prostate cancer can run in families, but pinpointing the underlying genetic basis has been challenging and previous studies have provided inconsistent results."

An estimated 240,000 men in the United States will be diagnosed with prostate cancer this year. While the HOXB13 gene mutation may account for only a small number of prostate cancer cases, it may provide clues about how this cancer develops and help to identify a group of men who might benefit from early or additional prostate cancer screening, the researchers said.